压敏片测量离体颈椎后路钢板固定术后关节突关节内压力的变化

Pressure variety of the facet joint using pressure sensitive film after cervical spine posterior fixation

目的:利用压敏片技术,测量颈椎后路钢板固定术后关节突关节内压力的变化,探讨颈椎后路手术后远期并发症的生物力学发病机制。方法:实验于2005-07/12在南方医科大学生物力学实验室完成。10具颈椎标本取自非颈椎外伤意外死亡的成年男性新鲜尸体。截取C1～T1节段,行后路C4全椎板切除、椎弓根螺钉固定术。将压敏片置于关节突关节内,在脊柱三维运动试验机上测C4,5量零载荷和2N·m载荷下,后伸、左/右侧弯、左/右旋转过程中关节突关节内压力的变化。结果:颈椎关节突关节内的压力值为中间大于两边,C3,,C5,大于C2,和C6,。在中立位时对关节突关节内压力变化不大;4637左/右侧弯时的压力将会增加,但差异无显著性意义(P>0.05);而左/右旋转和后伸运动时,各节段关节突关节内压力均明显增加,差异具有显著性(P<0.05),后伸位增加最为明显,差异具有非常显著性(P<0.01)。后伸位时关节突关节承受较大的负荷,脊柱内固定术后,压力值的大小依次为C3,>C5,>C2,>C6,,反映出后路手术后固定节段上位的压力变化大于下4637位节段。结论:颈椎后路钢板固定术后,邻近节段关节突关节内压力明显增加,可诱发邻近关节突关节的退变,从而引起相应的并发症。

AIM：To measure the pressure variety of facet joint using pressure sensitive film after cervical spine posterior fixation, and explore biomechanical mechanism of long-term complication after cervical spinal operations. METHODS： The experiment was carried out in the Laboratory of Biomechanics at Southern Medical University from July to December in 2005. Ten fresh adult corpse due to accidental death were adopted in this study to obtain cervical spine specimens （CI-TI）, then total laminectomy at C4 posterior pedicle screws were placed at C4 and C5 bilaterally. Pressure sensitive film was put into adjacent facet joints and pressures under 0 and 2 N-m loads were measured in extension, left/right lateral bending and axial rotation on a three-dimensional exercise testing machine. RESULTS： After cervical spine posterior operations, the pressure of adjacent facet joint was increased in the central part compared with both ends, higher in C3.4 and C5.6 than in C2.3 and C6.7. The pressure remained in neutral position, increased in left/right lateral bending （P 〉 0.05）, significantly increased in left-right axial rotation （P 〈 0.05）, and extremely significantly increased in extension （P 〈 0.01）. The pressure of facet joint in extension after spinal fixation was in order C3.4〉C5.6〉C2.3〉C6.7, indicating that the pressure variety of superior segment was more obvious than that of inferior segment. CONCLUSION： Cervical spine posterior pedicle screw plate fixation can increase the intra-articular pressure of adjacent facet joint. This might induce the degenerative changes at adjacent facet joint and bring corresponding complication.